diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a1b484..141dc96 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -60,8 +60,9 @@ INCLUDE(${CMAKE_ROOT}/Modules/GNUInstallDirs.cmake)
 INCLUDE(${CMAKE_MODULE_PATH}/MarsNweInstallDirs.cmake)
 
 # Add options for build
-option(ENABLE_DEBUG "Should we build with Debug?" ON)
-option(ENABLE_DEBUG_DOSUTILS "Should we build with Mars Nwe Dosutils Debugging?" OFF)
+option(ENABLE_DEBUG "Compile in MARS NWE debug logging code (DO_DEBUG)" OFF)
+option(ENABLE_DEBUG_BUILD "Build with debug compiler flags (-g3 -O0 -fno-omit-frame-pointer)" OFF)
+option(ENABLE_DEBUG_DOSUTILS "Enable NCP 17/02 debugging support for mars_dosutils" OFF)
 option(ENABLE_INTERNAL_RIP_SAP "Should we build Mars Nwe with Internal Router?" ON)
 option(ENABLE_SHADOW_PWD "Should we build Mars Nwe with Shadow Password Support?" ON)
 option(ENABLE_QUOTA_SUPPORT "Should we build Mars Nwe with Quota Support?" ON)
@@ -72,6 +73,28 @@ option(MARS_NWE_BUILD_DOSUTILS "Build DOS client utilities with Open Watcom" OFF
 
 set(MARS_NWE_SMART_ADMIN_GROUP "root" CACHE STRING "Unix group allowed to log in to the SMArT/nwwebui admin interface")
 
+
+# ENABLE_DEBUG controls the legacy DO_DEBUG code paths used by XDPRINTF().
+# ENABLE_DEBUG_BUILD is separate and only changes compiler flags / build type.
+# This allows release builds with compiled-in Mars debug logging, and also
+# explicit -g/-O0 builds when debugging the server with gdb or valgrind.
+if(ENABLE_DEBUG_BUILD)
+    if(NOT CMAKE_CONFIGURATION_TYPES)
+        set(CMAKE_BUILD_TYPE Debug CACHE STRING "Build type" FORCE)
+    endif()
+
+    add_compile_options(
+        $<$<COMPILE_LANGUAGE:C>:-g3>
+        $<$<COMPILE_LANGUAGE:C>:-O0>
+        $<$<COMPILE_LANGUAGE:C>:-fno-omit-frame-pointer>
+    )
+endif()
+
+if(NOT CMAKE_CONFIGURATION_TYPES)
+    set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS
+        "Debug" "Release" "RelWithDebInfo" "MinSizeRel")
+endif()
+
 IF (ENABLE_DEBUG)
     SET (MARS_NWE_DEBUG "1")
 ELSE (ENABLE_DEBUG)